Effect of fibrous capsule formation on doxorubicin distribution in radiofrequency ablated rat livers

In this study, we report the histological findings of a combined therapy using radiofrequency ablation and intratumoral drug delivery in rat livers, with special attention to wound-healing processes and their effects on drug transport in post-ablated tissue. Doxorubicin-loaded millirods were implanted in rat livers that had undergone medial lobe ablation. Millirods and liver samples were retrieved upon animal sacrifice at time points ranging from 1 h to 8 days. Results demonstrate a clearly defined area of coagulative necrosis within the ablation boundary. The wound-healing response, complete with the appearance of inflammatory cells, neovascularization, and the formation of a fibrous capsule, was also observed. At the 8-day time point, fluorescence imaging analysis showed a higher concentration of doxorubicin localized within the ablation region, with its distribution hampered primarily by fibrous capsule formation at the boundary. Given the variant nature of ablated liver, a mathematical model devised previously by our laboratory describes the data well up to 4 days, but loses reliability at 8 days. These results provide useful mechanistic insights into the wound-healing response after radiofrequency ablation and polymer millirod implantation, as well as the impact this natural corollary has on drug distribution.

Theoretical analysis and experimental evaluation of a Csl(TI) based electronic portal imaging system

This article discusses the design and analysis of a portal imaging system based on a thick transparent scintillator. A theoretical analysis using Monte Carlo simulation was performed to calculate the x-ray quantum detection efficiency (QDE), signal to noise ratio (SNR) and the zero frequency detective quantum efficiency [DQE(0)] of the system. A prototype electronic portal imaging device (EPID) was built, using a 12.7 mm thick, 20.32 cm diameter, Csl(Tl) scintillator, coupled to a liquid nitrogen cooled CCD TV camera. The system geometry of the prototype EPID was optimized to achieve high spatial resolution. The experimental evaluation of the prototype EPID involved the determination of contrast resolution, depth of focus, light scatter and mirror glare. Images of humanoid and contrast detail phantoms were acquired using the prototype EPID and were compared with those obtained using conventional and high contrast portal film and a commercial EPID. A theoretical analysis was also carried out for a proposed full field of view system using a large area, thinned CCD camera and a 12.7 mm thick CsI(TI) crystal. Results indicate that this proposed design could achieve DQE(0) levels up to 11%, due to its order of magnitude higher QDE compared to phosphor screen-metal plate based EPID designs, as well as significantly higher light collection compared to conventional TV camera based systems.

Sonographic sign of intermittent dilatation of the renal collecting system in 10 patients with vesicoureteral reflux

PURPOSE

Renal sonography is an accepted primary imaging modality for evaluating the pediatric urinary tract. We report a new sonographic finding associated with vesicoureteral reflux (VUR).

METHODS

Ten patients underwent sonographic evaluation of the kidneys and were noted to have intermittent renal collecting system dilatation that expanded and contracted during real-time scanning. These patients were further evaluated with voiding cystourethrography.

RESULTS

All 10 patients were proven to have VUR on the side of the sonographic abnormality. Four patients had bilateral VUR for a total of 14 refluxing renal units. Of these 14 renal units, 1 was sonographically normal. Five of the 14 renal units had grade V VUR that required surgical reimplantation of the ureter.

CONCLUSIONS

This new finding of intermittent renal collecting system dilatation may become an important predictor of VUR. The finding warrants further evaluation even when detected in patients not suspected of having VUR who are undergoing renal sonography for other reasons.

Enhancement of female esophageal and tracheoesophageal speech

Qi [J. Acoust. Soc. Am. 88, 1228-1235 (1990)] has demonstrated that (1) linear predictive (LP) methods can be used to separate vocal tract transfer functions from source functions of vowels produced by alaryngeal talkers and that (2) vowels synthesized with reconstructed transfer functions and totally synthetic voicing excitation sources have improved source-related properties over those present in the original vowels. Here, an extension of this work which is directed to the general goal of developing systems (devices) to enhance the quality of alaryngeal speech is reported. The specific goal of the present project was to determine whether speech, i.e., words spoken by female esophageal and tracheoesophageal talkers, could be enhanced by means of LP-based analysis and synthesis methods. Words spoken by four female alaryngeal talkers were analyzed and synthesized. A perceptual evaluation was completed to permit the quality of the synthetic and the original words to be compared. Listeners generally preferred to listen to the synthesized words, indicating that alaryngeal speech enhancement was accomplished.

Characteristics of voicing source waveforms produced by esophageal and tracheoesophageal speakers

Voicing source waveforms produced by 10 laryngectomized esophageal speakers, 12 laryngectomized tracheoesophageal speakers, and 10 age-matched, normal male speakers were obtained by inversely filtering flow functions recorded with a circumferentially vented mask. The data from these speakers was used to evaluate differences in source signal properties on a group basis. In a second analysis source signals produced by a single laryngectomized individual, capable of producing esophageal and tracheoesophageal speech in a highly proficient manner, were analyzed and compared. The overall results of this project provide an initial and novel description of voicing source signals produced by esophageal and tracheoesophageal speakers. The characteristics of these signals appear to be highly variable, particularly in comparison with the homogeneous pattern of source waves produced by age-matched, normal speakers. This initial description of voicing source signals produced by alaryngeal speakers is generally supportive of the hypothesis of differences in source properties among normal, esophageal, and tracheoesophageal voices.

Minimizing the effect of period determination on the computation of amplitude perturbation in voice

Current methods of computing amplitude perturbation present in human voices depend upon being able to accurately determine fundamental period. In this paper, two methods of estimating the amplitude perturbation present in human voices, which do not depend on accurate determination of the boundaries between fundamental periods, are described. In both of these methods, amplitude perturbation is computed as the variance of an ensemble of periods calculated after these periods have been aligned in time. In one method, time alignment is accomplished using zero-phase transformation. In the second method, an unconstrained dynamic programming procedure is used. The accuracy of estimating amplitude perturbation by these two methods is evaluated using synthetic and natural voice signals and is also compared with an estimation using zero-padding based time alignment. The unconstrained dynamic programming method is shown to provide accurate estimation of voice amplitude perturbation over a variety of signal conditions.

A homomorphic method for measuring secondary amplitude modulation

A homomorphic processing, software implemented method for measuring secondary amplitude modulation (AM) is described. The accuracy of measurement of this method was tested on a series of synthetically produced AM and vowel signals. The homomorphic method provided highly accurate measurement of modulation frequency and modulation index.

Serum and ascitic fluid levels of interleukin-1, interleukin-6, and tumor necrosis factor-alpha in patients with ovarian epithelial cancer

BACKGROUND

Recent studies have shown that multiple cytokines are secreted by ovarian epithelial cancer cells. Previous studies have shown that the cancer cell lines secrete macrophage colony-stimulating factor (M-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-1 (IL-1), interleukin-6 (IL-6), and transforming growth factor-alpha (TGF-alpha). Concomitantly, the serum levels of one of the growth factors (M-CSF) was found to be significantly elevated in patients with primary ovarian cancer and in second-look patients. The authors evaluated the serum levels of IL-1 alpha, IL-1 beta, IL-6, and tumor necrosis factor-alpha (TNF-alpha) in patients with primary ovarian epithelial cancer. These levels were then compared with cytokine concentration found in normal peritoneal fluid.

METHODS

Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of cytokines in normal peritoneal fluid, ascites, and serum.

RESULTS

In serum, TNF-alpha and IL-6 were significantly increased in primary ovarian cancer patients when compared with control subjects (P < 0.0001 for both cytokines). TNF-alpha and IL-6 were also significantly higher than the levels found in second-look patients (P < 0.007 for TNF-alpha, and P = 0.0002 for IL-6). The levels of IL-1 alpha and beta were not elevated in ovarian cancer. TNF-alpha in the ascites was higher when compared with normal peritoneal fluid and was statistically significantly different when a cut-off point between 71-110 pg was selected (P < 0.005). The levels of IL-6 in ascites from patients with primary ovarian cancer also showed a marked increase (P < 0.0001) when compared with peritoneal fluid from control subjects.

CONCLUSIONS

Levels of IL-1, IL-6, and TNF-alpha were determined in normal peritoneal fluid, ovarian malignant ascites, normal serum, and serum from patients with ovarian cancer. This study showed that the patients with ovarian cancer have elevated levels of IL-6 and TNF-alpha in serum and ascitic fluid. A larger study would help in evaluating the potential use of cytokines as tumor markers in ovarian cancer.

The apical oblique view of the clavicle: its usefulness in neonatal and childhood trauma

We analyzed clavicular radiographs of 26 patients with a history of trauma. The apical oblique projection of the clavicle was obtained with the injured side of the patient angled 45 degrees towards the X-ray tube and a 20 degrees cephalad angulation of the X-ray beam. This view proved to be more informative than the routine apical anteroposterior projection. It is especially effective in detecting nondisplaced fractures of the middle third of the clavicle in neonates and children. To verify our findings, we obtained apical anteroposterior and oblique radiographs of a specimen adult clavicle. On the oblique view with 20 degrees cephalad angulation of the X-ray beam, the measurements of the projected lengths of the anatomical specimen, especially those of the middle portion of the clavicle, were very close to the corresponding anatomical lengths.

Strategies to manage the post-MI patient with ventricular arrhythmias

The occurrence of late ventricular arrhythmias after acute myocardial infarction is common. The available data do not support the treatment of asymptomatic premature ventricular complexes or asymptomatic non-sustained ventricular tachycardia after acute myocardial infarction. Signal-averaged electrocardiograms, perhaps in combination with Holter recording and measurements of left ventricular function show promise as potential markers of risk for subsequent sudden death or sustained ventricular tachycardia. Nevertheless, the appropriate treatment of any high-risk but asymptomatic subset of patients has not been established. Patients experiencing sustained ventricular tachycardia after acute myocardial infarction and survivors of late ventricular fibrillation are at high risk of early cardiac mortality and require aggressive treatment which may consist of serial electrophysiologic testing to evaluate drug therapy, arrhythmia surgery, or placement of an automatic implantable cardioverter defibrillator.

Tone in Thai alaryngeal speech

The perception and production of linguistic tone was investigated in utterances spoken by Thai alaryngeal speakers. Thai is a tone language with five phonemic tones. High-quality tape recordings of five monosyllabic words produced by 2 esophageal, 1 electrolaryngeal, and 5 normal, native Thai speakers were subjected to perceptual and acoustic analysis. Results from the phonemic identification tests indicated that tones produced by alaryngeal speakers were not only perceived at much lower levels of accuracy than those produced by normal speakers, but the patterns of tonal confusions for alaryngeal speakers were also dissimilar to those for normal speakers. Results from fundamental frequency (Fo) analysis revealed that the performance deficit of alaryngeal speakers could be related to specific characteristics of their Fo contours. Findings are interpreted to highlight the importance of (a) language, (b) type of prosody, (c) form of alaryngeal speech, and (d) Fo level and direction on linguistic assessments of Fo control in alaryngeal speech.

Voice onset time in Thai alaryngeal speech

The perception and production of voicing contrast was investigated in utterances spoken by Thai alaryngeal speakers. Thai exhibits a three-category voicing distinction for bilabial /b, p, ph/ and alveolar /d, t, th/ stops and a two-category distinction for velar [k, kh] stops. Voice onset time (VOT) was measured in word-initial stops of words produced in isolation by 2 Thai esophageal speakers and 1 Thai user of an electronic artificial larynx. These measurements were compared with published VOT values for the same words spoken by 5 normal Thai speakers. Both esophageal speakers were capable of signaling voicing distinctions for /b, d/ and /p, t, k/. The electrolaryngeal speaker was able to signal /p, t, k/ only. Thai alaryngeal speakers were generally unsuccessful in signaling /ph, th, kh/. A cross-linguistic comparison to VOT in English suggests that no more than two voicing categories can be distinguished in these two forms of alaryngeal speech. Findings are interpreted to illustrate that the realization of stop voicing contrasts in alaryngeal speech depends on the number of voicing categories in a language, the relative positions of the voicing categories on the VOT continuum, and the form of alaryngeal speech.

Infantile hemangioendothelioma of heterotopic intrathoracic liver associated with diaphragmatic hernia

An autopsy of a six-hour-old term neonate, who died during surgery for repair of a left diaphragmatic hernia, revealed an infantile hemangioendothelioma type I arising in a heterotopic lobe of liver in the left thorax. The upper pole of the tumor was attached by fibrovascular tissue to the lower lobe of the left hypoplastic lung. A pedicle attached to the lower pole of the heterotopic liver pierced through the diaphragm to the left lobe of the normal liver. This case is an example of an unusual association of congenital malformation and putative neoplasm.

The air bronchogram: sonographic demonstration

A new sonographic pattern of pulmonary consolidation associated with air-filled bronchi in children is presented. The consolidated area of the lung is usually hypoechoic, poorly defined, and wedge-shaped. The air-filled bronchi produce linear, high-amplitude branching echoes that converge toward the lung root. Posterior acoustic shadowing and reverberation artifacts are seen accompanying the proximal large bronchi. A comparative study is presented in which 30 pediatric patients with clinical and radiographic evidence of pneumonia were sonographically evaluated. Twenty-eight patients were successfully examined with sonography. The cases were divided into three groups: (1) consolidated lung without pleural effusion (19 patients); (2) consolidated lung with small pleural effusion (five patients); and (3) consolidated lung with partial compression atelectasis due to large pleural effusion (four patients).

Colonic obstruction in a child with von Recklinghausen's neurofibromatosis

A child is reported who developed partial colonic obstruction from an intussuscepting polypoid mass in the transverse colon. A 5 cm plexiform ganglioneurofibroma was found at laparotomy. Examination of the entire gastrointestinal tract revealed no other neurogenic tumors. Gastrointestinal involvement by neurofibromatosis in children is rare; however, children with von Recklinghausen's disease who complain of vague abdominal symptoms should be evaluated for gastrointestinal tumors.

Airway resistances of Blom-Singer and Panje Low Pressure tracheoesophageal puncture prostheses

Airway resistances were calculated for two newly commercialized tracheoesophageal (TE) puncture prostheses: the Panje Low Pressure Voice Button and the Blom-Singer Low Pressure device. The airway resistances of newly commercialized Panje Low Pressure devices could not be distinguished from those calculated for previously commercialized, Regular Pressure Voice Button devices. Airway resistances of Blom-Singer Low Pressure devices increased systematically as a function of flow rate. Findings are compared with existing data to provide readers with an opportunity to evaluate the relative efficiency of air shunting among contemporary TE puncture prostheses. Results are interpreted in relation to their implications for selecting surgical-prosthetic options for laryngectomized patients.